/// <summary>
/// Generates a list containing the decision variables of the branches, which can be used to derive a single decision variable of the constraint tree.
/// <para>Basically, this generates the carthesian product of the decision variables of the branches</para>
/// This can be used to generate constraints of sort:
/// Tree-Constraint-1-Satisfied = Branch-A-Satisfied OR Branch-B-Satisfied
/// </summary>
/// <param name="constraintTree"></param>
/// <returns></returns>
public static IEnumerable <IEnumerable <string> > GetSatDVarParts(this ConfigurationConstraintTree constraintTree)
{
if (constraintTree.IsCombination)
{
List <List <string> > branchDvarLists = new List <List <string> >();
IEnumerable <IEnumerable <string> > dvarsCarthesianProduct = new[] { Enumerable.Empty <string>() };
// For each branch we find its satisfaction decision variables
foreach (var branch in constraintTree.ConstraintBranches)
{
List <String> branchDvars = branch.GetSatDVarNames();
if (branchDvars.Count > 0)
{
branchDvarLists.Add(branch.GetSatDVarNames());
}
}
// Then the carthesian product of the decision variables is calculated
dvarsCarthesianProduct = branchDvarLists.Aggregate(
dvarsCarthesianProduct,
(accumulator, sequence) =>
from accseq in accumulator
from item in sequence
select accseq.Concat(new[] { item }));
return(dvarsCarthesianProduct);
}
// if this is not a combination constraint tree return empty list
return(new List <List <string> >());
}
/// <summary>
/// Creates a constraint tree for a set of components from a domain constraint.
/// </summary>
/// <param name="parent">The parent of the current constraint tree</param>
/// <param name="derivedFrom">The domain constraint from which the tree is derived</param>
/// <param name="components">The components for which to apply the relevant DomainConstraint</param>
/// <param name="log">The processing log</param>
internal ConfigurationConstraintTree(ConfigurationConstraintTree parent, DomainConstraint derivedFrom, List <GKOComponent> components, Log log)
{
if (derivedFrom == null)
{
throw new ArgumentNullException("The derived from domain constraints has to be set for a configuration constraints tree!");
}
this.Parent = parent;
// assigning the right DomainConstraint
if (derivedFrom is ITransformDomainConstraint)
{
this.derivedFrom = (derivedFrom as ITransformDomainConstraint).TransformConstraint();
}
else
{
this.derivedFrom = derivedFrom;
}
if (this.DerivedFrom is DomainConstraintCombination)
{
this.CreateFromCombinationConstraint((DomainConstraintCombination)this.DerivedFrom, components, log);
}
else
{
this.CreateFromNormalConstraint(this.DerivedFrom, components, log);
}
}
/// <summary>
/// Finds the list of satisfaction variables for the current tree.
/// Takes in consideration the branches of the tree (if any), but does not return their decision variables.
/// If the tree has configuration constraints returns a list of their decision variables names.
/// </summary>
/// <param name="constraintTree"></param>
/// <returns></returns>
public static List <string> GetSatDVarNames(this ConfigurationConstraintTree constraintTree)
{
List <string> dVarNames = new List <string>();
if (constraintTree.IsCombination)
{
IEnumerable <IEnumerable <string> > dvarsCarthesianProduct = constraintTree.GetSatDVarParts();
// Create the decision variables based on the included branch variables
foreach (var dVarList in dvarsCarthesianProduct)
{
dVarNames.Add(constraintTree.GetSatDVarName(dVarList));
}
}
else
{
foreach (var constraint in constraintTree.ConfigurationConstraints)
{
dVarNames.Add(constraint.GetSatDVarName());
}
}
return(dVarNames);
}
/// <summary>
/// Generates the satisfaction decision variable name for the current constraint tree, when using a specific decision variables of the branches
/// </summary>
/// <param name="constraintTree"></param>
/// <param name="parts">An ordered list of the chosen decision variables of the included branches</param>
/// <returns></returns>
public static string GetSatDVarName(this ConfigurationConstraintTree constraintTree, IEnumerable <string> parts)
{
return(string.Format("{0}-{1}-satisfied", constraintTree.DerivedFrom.Name, parts.Aggregate((x, y) => x + "-" + y)));
}
